Keep $QUTE_COUNT unset if a count is not given

qutebrowser/browser/commands.py

@@ -1252,9 +1252,11 @@ class CommandDispatcher:
         env = {
             'QUTE_MODE': 'command',
             'QUTE_SELECTED_TEXT': selection,
-            'QUTE_COUNT': str(count), # must be a string
         }
 
+        if count is not None:
+            env['QUTE_COUNT'] = str(count) # must be str
+
         idx = self._current_index()
         if idx != -1:
             env['QUTE_TITLE'] = self._tabbed_browser.widget.page_title(idx)

tests/end2end/data/userscripts/hello_if_count

@@ -4,7 +4,7 @@ if [ "$QUTE_COUNT" = "5" ]; then
 
     echo "message-info 'Count is five!'" >> "$QUTE_FIFO"
 
-elif [ "$QUTE_COUNT" = "None" ]; then
+elif [ -z "$QUTE_COUNT" ]; then
 
     echo "message-info 'No count!'" >> "$QUTE_FIFO"